首页|Fluid inclusions, isotopes, and geochronology data constraints on the mineralization of the Carboniferous volcanogenic massive sulfide Xiaorequanzi Cu-Zn deposit in the East Tianshan, NW China

Fluid inclusions, isotopes, and geochronology data constraints on the mineralization of the Carboniferous volcanogenic massive sulfide Xiaorequanzi Cu-Zn deposit in the East Tianshan, NW China

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  • NSTL
  • Elsevier
The Xiaorequanzi Cu-Zn deposit is the first and only volcanogenic massive sulfide (VMS) Cu-Zn deposit discovered in the Carboniferous volcanic-sedimentary rock series of the East Tianshan, Xinjiang. The mineralization includes stratiform, stringer/stockwork, volcanic hydrothermal-related veinlet, and subvolcanic-related vein/veinlet. The exhalative sedimentary period contributed to the majority of the Cu-Zn resource and can be subdivided into three stages: (I) stratiform (Ia) and stringer/stockwork (Ib) mineralization is represented by layered, lenticular, tabular, vein, and irregular Cu-Zn-(Au) orebodies, (II) volcanic hydrothermal-related vein mineralization is defined by pyrite-quartz +/- carbonate veinlets, and (III) subvolcanic-related vein/veinlet mineralization is associated with albitophyre and dacite porphyry. Fluid inclusions study reveals that the mineralizing fluids in stage I are characterized by moderate-low temperature (peak at 160-240 degrees C) and low salinity (peak at 5.0-10.0 wt% NaCl eqv.). The composition of He-Ar and H-O isotopes indicate that stage I mineralizing fluids were derived from deep-circulation seawater mixed with magmatic fluids accompanied by fluid mixing. Sulfides from stage I record a range of 834S values between 3.7 and 7.8%o, suggesting that the mineralizing sulfur was derived from seawater sulfate and volcanic rocks by thermochemical sulfate reduction. The mineralizing fluids in stage II display low temperatures (peak at 140-180 degrees C) and low salinities (peak at 5.0-7.0 wt% NaCl eqv.), which could indicate continuous cooling of magmatic fluids and input of seawater accelerated the precipitation of pyrite in this stage. The mineralizing fluids in stage III are characteristic of bimodal distribution temperatures (peak at 160-220 degrees C and 240-280 degrees C) and salinity (peak at 6.0-8.0 wt% NaCl eqv. and 9.0-12.0 wt% NaCl eqv.). The composition of H-O isotopes indicate that stage III mineralizing fluids were derived from magmatic fluid mixed with seawater accompanied by fluid boiling. The 834S values range from 1.5 to 4.0%o, implying a magmatic sulfur origin. Zircon U-Pb dating of mineralization-hosting tuff and dacite porphyry yielded ages of 354.5 +/- 3.9 Ma and 341.9 +/- 3.1 Ma, respectively. Combining the previous Re-Os and U-Pb ages of the deposit, we conclude that the Xiaorequanzi Cu-Zn deposit is spatially and genetically associated with the volcanic exhalative sedimentation at 352-357 Ma and subvolcanic intrusion at 342-345 Ma, respectively.

Fluid inclusionsIsotopesGeochronologyVolcanogenic massive sulfide (VMS)Xiaorequanzi Cu-Zn depositEast TianshanPORPHYRY COPPER-DEPOSITSULFUR ISOTOPEOROGENIC BELTNOBLE-GASESHYDROTHERMAL FLUIDSCHIMNEY MINERALSSTABLE-ISOTOPEPACIFIC RISEVENT FLUIDSGEOCHEMISTRY

Zhang, Zhixin、Li, Ning、Geng, Xinxia、Wang, Jinlin、Wang, Wei、An, Shaole、Zhang, Zhenlong

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Chinese Acad Sci

Taiyuan Univ Technol

Chinese Acad Geol Sci

2021

10.1016/j.oregeorev.2021.104505

Ore Geology Reviews

Ore Geology Reviews

EISCI
ISSN：0169-1368
年,卷(期)：2021.139(Pt.B)
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